This invention relates to the regulation of power applied from an AC source to electrical loads of the heater element type.
Power regulating systems for incandescent lamps and similar electrical loads connected to an AC power source through a power switch such as a triac, are already well known as disclosed for example in U.S. Pat. No. 4,360,783 to Nagasawa et al. Such regulating systems sense the voltage across the load from which information is transmitted by a feedback loop to the actuator for the power switch, the feedback loop including a comparator receiving inputs from a synchronizing signal generator and an error threshold detector to which a load voltage sensor is connected.
The foregoing type of power regulating systems have not been entirely satisfactory in providing precision control and accommodating AC power sources having somewhat different operating frequencies, without special adjustment. Further, the lack of precision control by prior regulating systems has been aggravated by the occurrences of line voltage transients and development of excessive control signal oscillations. Attempts to correct such problems normally require complex and expensive circuit modifications.
It is therefore an important object of the present invention to provide a power regulating system of the aforementioned type which avoids the drawbacks thereof in a relatively simple and cost effective manner.